Answer:
The key signtaure is E flat major, this is evident from going to the second to last flat; that will always be the key signature when pertaining to flats
Step-by-step explanation:
Because the signature is E flat major, there are three flats, and those flats are B flat, E flat, and A flat. This means that all three of these notes in the key signature will be played as flats. This a common rule when pertaining to any key signature. Although this does not account for accidentals, if a note has a key sign before it, then that note is to be played as such no matter the key signature. Lemme know if you need more of an explanation!
Hope this helps! :)